On Mon, Nov 11, 2013 at 05:13:41PM -0200, Fabio Estevam wrote: > From: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx> > > Currently mx23_check_transcription_stamp() uses chip->buffers->databuf > as its buffer, which is allocated by nand_scan_tail(). > > Since commit 720e7ce5 ("mtd: gpmi: remove the nand_scan()"), > mx23_check_transcription_stamp() is called before nand_scan_tail(), which causes > a NULL pointer dereference: > > [ 1.150000] NAND device: Manufacturer ID: 0xec, Chip ID: 0xd7 (Samsung NAND 4GiB 3,3V 8-bit), 4096MiB, page size: 4096, OOB size: 8 > [ 1.160000] Unable to handle kernel NULL pointer dereference at virtual address 000005d0 > [ 1.170000] pgd = c0004000 > [ 1.170000] [000005d0] *pgd=00000000 > [ 1.180000] Internal error: Oops: 5 [#1] ARM > [ 1.180000] Modules linked in: > [ 1.180000] CPU: 0 PID: 1 Comm: swapper Not tainted 3.12.0 #89 > [ 1.180000] task: c7440000 ti: c743a000 task.ti: c743a000 > [ 1.180000] PC is at memcmp+0x10/0x54 > [ 1.180000] LR is at gpmi_nand_probe+0x42c/0x894 > [ 1.180000] pc : [<c025fcb0>] lr : [<c02f6a68>] psr: 20000053 > [ 1.180000] sp : c743be2c ip : 600000d3 fp : ffffffff > [ 1.180000] r10: 000005d0 r9 : c02f5f08 r8 : 00000000 > [ 1.180000] r7 : c75858a8 r6 : c75858a8 r5 : c7585b18 r4 : c7585800 > [ 1.180000] r3 : 000005d0 r2 : 00000004 r1 : c05c33e4 r0 : 000005d0 > [ 1.180000] Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel > [ 1.180000] Control: 0005317f Table: 40004000 DAC: 00000017 > [ 1.180000] Process swapper (pid: 1, stack limit = 0xc743a1c0) > > In order to fix this problem, allocate the buffer locally via kzalloc(). > > Also, as mx23_check_transcription_stamp() can return en error code now, adapt > the logic in mx23_boot_init() to take this into account. > > Cc: <stable@xxxxxxxxxxxxxxx> # 3.12 > Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx> > --- > Changes since v1: > - Drop sizeof(*buffer) from size calculatio in kzalloc (Brian Norris) > - Propagate the error if mx23_check_transcription_stamp returns a negative > error code (Brian Norris) Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx> I'll give Huang a chance to comment before pulling this in. Thanks, Brian -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html